Welding



Oct. 18, 1960 w. scHcHTER ETAL 2,957,070

WELDING Filed March 25, 1958 3 Sheets-Sheet 1 Oct. 18, 1960 w.sci-ACHTER ET AL WELDING 3 Sheets-Sheet 2 Filed March 25, 1958 InventorOct. 18, 1960 Filed March 25, 1958 w. scHcHTER ETAL 2,957,070

WELDING 3 Sheets-Sheet 3 nitecl States Patent Q WELDING Willy Schchter,Heinz Schumacher, and Herbert Lepold, Frankfurt am Main, Germany,assignors to Voigt 8c Haeffner A.G., Frankfurt am Main, Germany FiledMar. 25, 1958, Ser. No. 723,758 'Claims priority, application GermanyMar. 26, 1957 8 Claims. (Cl. 219-79) The invention relates between metalparts.

Apparatus for making one `or more joints between at least two metalparts which `are of any desi-red crosssection and which `are disposed atany desired angle to one .another in one or more planes are known. Inthe case of structural steel latticework, mats or like objects made fromhat or round stock a number of joints 'are made in a single planebetween the longitudinal and transverse parts thereof. In .themanufacture of lattice :gir'ders made of strip or wire material, whichserve as reinforcement `for concrete in the same way as the aforesaidsteel latticework, the components are disposed at an angle to oneanother in three dimensions and the joints between them are likewisearranged spatially.

The `aforementioned steel mats have hitherto been made by a process inwhich the components are passed stepwise through a welding machine, thewelding always taking place when the components are stationary. Whenlattice girders .are likewise made by an interittent feeding process.similar to the known process for the construction of steel mats, animprovement in the method of production is obtained but something stillbetter is called for in order to facilitate a truly cheapmass-production of such lattice girders.

The invention is based on this consideration and aims to provide :amachine by means of which spot-welded uniplanar or three-dimensionalarticles vcan be produced in large numbers at relatively low costs. Wehave found that such articles can be mass-produced cheaply if themachine for making them operates continuously as Well as fullyautomatically because any loss of time caused by the standstill periods`in the intermittent process and the resultant reduction in the rate ofoutput are thus avoided. Apparatus operating on the intermittent processrequires .that one `or more loops of the material to be welded be formedbetween the welding station and the reels supplying the material, so asto compensate for the jerky feed of the material through theinstallation. The space occupied by these compensating loops necessarilylincreases the overall dimensions of the installation and its weight andthe invention thus dispenses with cornpensating loops.

In accordance with the invention a machine for making welded articles`is therefore so designed that one or more components for the articleare fed continuously lengthwise through the machine, connecting orlattice members for the said components being introduced at any desiredyangle to the direction of feed to be supported thereby after .thecomponents have been fed a predetermined distance, whereafter theconnecting or lattice members are spot-welded to the components carryingthem by to making spot-welded joints l means wh-ich participate in thefeeding movement during welding and which are returned to their startingposition after welding.

The invention will be more fully explained with reference to theexamples illustrated in the accompanying drawings, in which:

Fig. `1 is a diagrammatic side View of a machine lfor making uniplanarlattice work or mats,

Fig. 2 is a similar view of a machine for making threedimensionallattice girders, and

Fig. 3 is a schematic view of a control system for the machine of Fig. 1or 2.

Referring to Fig. 1, the machine essentially comprises reels 1containing wire material, wire trueing means 2, a main drive 3 with drawchecks 4, welding means 5 proper and severing means 6. The endless roundsteel wires 7 (basic mat material) drawn continuously at constant speedfrom the reel 1 and guided in parallel juxtaposed relationship arepulled through the trueing means 2 byl the main drive 3 with the aid ofthe pairs of draw checks 4 and guided into the welding device 5.

In an installation disposed laterally of the aforementioned arrangement,but not shown lin the drawing, transverse connecting or lattice members8 for the wires 7 are also .drawn lfrom reels, trued, cut to lengths inconformity with the desired mat width and thereafter fed to the magazine9.

A welding carriage 10 is provided with a drive 11, which drives a camdisc 12 controlling ejector elements at the magazine 9. The cam Vdisc 12acts on two levers 13, 14. The lever `13 blocks all the members 8 in themagazine 9 except the one nearest the magazine outlet which -is held bythe lever 14. When the lever 14 is lifted, the outlet from the magazineis freed and a connecting member S is `released to be ejected under theinfluence of `lingers 15. The ejected member 8 is received in one of theseatings 16, which are advanced at the same speed as the basic matmaterial 7. The ejector elements at the magazine could be controlled bythe main drive 3 for the continuous .feed of the basic mat material 7 instead of by the drive for the welding carriage 10. It would also bepossible to control the ejection of .the connecting members 8 from themagazine 9 by non-mechanical means, for example by means ofphotoelectric cells. Such cells, as is shown in Fig. 3, may be actuatedby the passing connecting members 8 and/ or seatings 16 and couldenergise an electromagnet which opens or closes a flap at the outletfrom the magazine 9.

The drive 11 for the welding carriage 10 `at the same time operates aconveyor chain yfor the seatings 16 and a crank .guide 17. The crankguide must be so designed and its speed must be so chosen that onerotation thereof produces a forward movement of the basic ma-t materialby the amount of its pitch, i.e. :by the distance between two connectingmember 8 in the finished latticework. This ensures synchronous speedsbetween the basic mat material 7 and the welding carriage 10. Thecommencement of the movement of the welding carriage 10 could also beinitiated by photoelectric cells influenced by ejection of theconnecting members 8 from the magazine.

Fig. `3 illustrates a control mechanism incorporating an optical cell 2'-upon which impinges a light ray 1'. The cell 2' .is so positioned thatthe seatings of the connecting members 3 (corresponding to parts 16 and8, respectively, .in Fig. l) pass between the non-represented source oflight ray 1 and the cell 2'; the latter then opens a circuit includingan electromagnet 4 which operates a closure flap 5 on thenon-represented magazine Afor connecting members 3'. The flap 5' thenallows one or more connecting -members 3' to drop on to the wires 6',the latter corresponding to wire or wires 7 in Fig. l. Fig. 3 furthershows an operative connection between the optical cell 2 and anonrepresented welding carriage corresponding to part 10 in Fig. l. Theconnection comprises an electromagnet 7 which is energized by member 2'when the light ray 1 is interrupted by a connecting member 3.Electromagnet 7 then closes two contacts 9 to energize a furtherelectromagnet 10 in the circuit of a clutch 11. The assembly of parts10', l1 is installed on the ouput shaft of a continuously running motor(not shown) which can bring about movements of the welding carriage;thus, when the clutch 11'v is. operated by the energized electromagnetI', the forward movement of the welding carriage and of the 4electrodescommences irrimedi- -ately. The period of time during which this feedtakes place may be controlled by an electronic timing device which, asis known, is variable within wide limits.

The welding carriage yiii supports electrodes i8, which are applied bymeans. of pressure cylinders 19 at the instant when a connecting memberS is located immediately below the-electrodes 18 and when the speed ofthe welding carriage is identical in direction and magnitude with thespeed of the basic mat material 7. The electrodes 18 are also applied.by the drive ll'through a cam-controlled slide valve (not shown). Atraverse 20 vmounted on. rollers opposite the welding carriage lit-andsupporting the cylinders 19 is rigidly coupled to the` welding carriage10 by locking means 21. As soon as the electrodes 18 have movedtogether, the locking means 21 are released in order that differences inthe travel .of the traverse 20 and the welding carriage 10 occasioned byany small ydiierences in speed between the matenial 7, 8 to be weldedand the welding carriage 1l) may. be cancelled out. Thus, lthe aforesaidmeans produce complete synchronism between the speed of the Weldingcarriage and the speed of advance of the basic ma-t material. When thewelding operation has been completed, the carriage iti returns to itsstarting position. This return movement of the carriage may be selfactuated in that, for example, the carriage makes contact with `a limitswitch, the impulses -from which energize an electronic control. Ofcourse the return movement of the welding carriage may 1also be electedby purely mechanical means.

Figure 2 illustrates :a machine for making lattice girders,l that is Itosay, girders in which the upper and lower booms of any desiredcross-sectional shape are interconnected by means of lattice or webmembers to Lform three-dimensional structures of high mechanicalstrength. Y Figure 2 shows only those partsV which are necessary -for anunderstanding of the manner of operation of the lattice-.girder machine.Parts which are substantially identical with parts of theconstrue-tional example illustrated in Figure l have been omitted. Theseinclude the reels, from which the material for the upper and lower boomsof .the girder are withdrawn continuously in endless lengths, the driveand the means for the continuous feed of the boom material through themachine and the severingV means.

In Figure 2, the eject-ion of the connecting or lattice members, whichhave irst been bent into V-shape, from a magazine 25 is ylikewiseeffected by a cam disc 26 which acts through a lever 27 on a locking andreleasing member 23. The latter controls the ejector elements, and twolattice members 29, 3tl-fall from the storage device at a time. Thesetwo lattice members are -frst carried along in the direction ofadvancement under the action of the forward feed movement of the upperboom 31 and the lower booms 32a, 321). After a predetermined distance, apush member 33 of an aligning device 34 acts on the foremost latticemember 30 and tilts it into its proper position in relation to the upperand lower booms, this position being evident vfrom the drawing.

The lattice members 29, 30 are held in seatings 35 in the region of thelower booms, the seatings being carried by a conveyor belt 36operatively coupled to the welding carriage 37. After having covered apredetermined distance, theupper boom 3l, and .the two. lattice membersrestingy thereon pass under the first welding device.' 3S, theelectrodes 3S, 4t of which; descend. and

spot-weld the two lattice members to the upper boom 31. After travellingsome further distance, the lattice members are welded to the` two lowerbooms by the welding device 41, which also comprises two electrodes 42,43 each of which spot welds the end of one lattice member to itsrespective lower boom. As in Fig. l, the welding `devices 38, 41 areadvanced during welding at a. speed which is the same .as that withwhich the booms are -fed through the machine. Y

Synchronisrn between the welding carriage and the feed means for theboom material may be effected, -for example, in that the drive whichdetermines the Ifeeding speed of the boom material also drives agenerator, having la frequency which determines the speed of the drivefor the welding carriage. Alternatively, a directcurrent motor could beemployed to drive the welding carriage, the speed of rotation of themotor being governed by the main drive for the boom material.

We claim:

l. A machine for making welded articles comprising, in combination: asupply of'a first component of the articles; a supply of secondcomponents of the articles; means for continuously yfeeding the firstcomponent from said firstV mentioned supply :at a `given speed in a rstdirection; means for delivering second components from said lastmentioned supply at intervals in :a second direction at an angle to saidfirst direction into supported contact with the rst. component whereuponthe rst component and the second components advance in unison in saidfirst direction; means for spot-welding the. second components to thefirst component; means for irst advancing said spot-welding means from astarting position toward each one of the second components while thelatter is supported .by and moves with the first component and lforthereupon advancing the spot-welding means in said first direction at aspeed at which the iirst component is -fed whereby the second componentsare welded to the first component while advancing therewith in saidfirst direction; means for returning the spot-welding means yinto saidstarting position after the completion of a welding operation; amagazine for receiving said supply of second components, the magazinehaving a flap; spaced seatings for the second `components operativelyconnected `for movements with the feeding means in said first direction;electromagnet means operatively connected with said'iiap; and an opticalcell `for energizing said electromagnet means and so installed in saidmachine as to `be inuenced by the passage of said seatings where-- by toenergize said electromagnet means, the latter operating said flap torelease at least one second component from said magazine.

'2. A machine for making welded articles comprising, in combination: :asupply of a first component of the articles; a supply of secondcomponents of the anticles; means for continuously feeding the irstcomponent from said iirst mentioned supply at a given speed in a iirstdirection; means for delivering second components from said lastmentioned supply at intervals in a second direction 4at an angle to saidii'rst direction into supported contact with the first `componentwhereupon the iirst component and the second components advance inunison in said rst direction; means for spot-welding thersecondcomponents to the iirst component; means for rst advancing saidspot-welding means from a starting position toward each one of thesecond components while the latter is supported by `and moves with thefirst component and for thereupon -advancing the spot-welding means insaid iirst direction at a speed at which the first component is fedwhereby the second components are welded to the iirst component whileadvancing therewith in said first direction, said advancing meanscomprising a carriage, means `for moving said carriage, and an opticalcell for operating said last mentioned. means so installed in saidmachine as tov be influenced by each second .component delivered tromsaid. supply ofV second components ,for causing movements of thecarriage in said rst direction; and means for returning the spot-Welding means into said starting position after the completion of :awelding operation.

3. The combination as set forth in claim 2, wherein the means foradvancing said spot-welding means comprises a carriage and `furthercomprising means for synchronizing the movements of the feeding means ofthe carriage in said first direction, said synchronizing meanscomprising ya crank gul-7de so connected with said feeding means as toperform `one revolution when the first component is fed a distance equalto that between successively delivered second components.

4. A machine for making welded articles comprising, in combination: aSupply of a first component of the articles; a supply of secondcomponents of the articles; means for continuously feeding the firstcomponent from said first mentioned supply at a given speed in a firstdirection; means for delivering second components from said lastmentioned supply at intervals in a second direction -at an :angle tosaid first direction into supported contact with the first componentwhereupon the first component and the second components advance inunison in said first direction; means for spot-welding the secondcomponents to the first component; means for first advancing saidspot-welding means from a starting position toward each one of thesecond components while the latter is supported by the moves with thefirst component and for thereupon advancing the spot-welding means insaid rst direction at a speed at which the first component is fedwhereby the second components are welded to the first component whileadvancing therewith in said rst direction; means `for returning thespot-welding means into said starting position after the completion of awelding operation; and severing means connected for movements with saidspot-welding means Iand situated rearwardly of the latter las seen insaid first direction for severing the first component after welding ofat least one second component thereto.

5. A machine for making lattice girders comprising, in combination: atleast one upper and at least one lower reel of wire-like material; meansfor continuously drawing the material from said reels in parallelismwith each other in a rst direction, the material drawn from each upperIreel constituting the upper boom and the material drawn from each lowerreel constituting the lower boom of the girders; a magazine; a supply ofprefabricated lattice members in said magazine; means for discharginglattice members from said magazine into supported contact with saidbooms in a second direction substantially perpendicular to said firstdirection whereupon the lattice members move with the booms in saidfirst direction; means for positioning and holding the lattice membersin spaced relationship on the booms; means for spotwelding the latticemembers to the booms; means for advancing said spot-Welding means firstfrom a starting position toward the lattice members vWhile the latterare supported and positioned on and move with the `booms in said firstdirection, and for thereupon moving said Spotwelding means in said firstdirection whereby the lattice members are welded to the booms whileadvancing with the latter in said first direction; `and means forreturning the spot-welding means into starting position after thecompletion of a welding operation.

6. The combination as set forth in claim 5, wherein the means foradvancing `said spot-welding means cornprises a carriage and saidpositioning means comprises a conveyor connected with said carriage andincluding seatings for holding the lattice members while the latter arein supported contact with the booms.

7. The combination as set forth in claim 6, wherein the means foradvancing said `Spot-welding means comprises a carriage, and furthercomprising means for synchronizing the movements of said carriage withthe movements of said drawing means.

8. The combination as set forth in claim 7, wherein said synchronizingmeans comprises generator means driven by `said drawing means andoperatively connected with said carriage in such manner that thefrequency thereof determines the speed of said carriage.

References Cited in the file of this patent UNITED STATES PATENTS1,448,566 Muller et al. Mar. 13, 1923 1,554,030 Reed Sept. 15, 19251,694,081 Reed Dec. 4, 1928 1,866,382 White July 5, 1932 2,414,905Seltzer Ian. 28, 1947 2,422,829 Fotie June 24, 1947 2,497,260 GriesemerFeb. 14, 1950 2,529,556 Keller Nov. 14, 1950

